BACKGROUND:Between October 2013 and March 2014, French Polynesia experienced the largest Zika virus (ZIKV) outbreak ever described before the emergence of ZIKV in the Americas in 2015. As arbovirus transfusion-transmitted (TT) infections have been previously reported, we hypothesized that transfusion of blood products could also transmit ZIKV.STUDY DESIGN AND METHODS:Mitigation strategies to prevent ZIKV-TT infections included nonspecific measures and the implementation of a laboratory developed ZIKV-specific nucleic acid testing (NAT) assay. Donor sera were tested in pools of 3 and constitutive sera of ZIKV-reactive pools were tested individually. Donor sera were tested prospectively and retrospectively. A posttransfusion follow-up of a patient transfused with ZIKV RNA-reactive blood products was implemented.RESULTS:NAT detected 42 blood donor sera as ZIKV RNA reactive of 1505 tested (2.8%). Thirty ZIKV RNA-reactive blood products collected before the implementation of NAT were transfused to 26 recipients. Posttransfusion investigations were conducted by the hemovigilance unit and data were available for 12 recipients. Symptomatic ZIKV-TT infections were not reported.CONCLUSION:Predonation screening of blood donors, postdonation information, products discard, and quarantine of blood products were not effective enough to prevent transfusion of ZIKV RNA-reactive blood products. ZIKV NAT was an effective measure once implemented to prevent transfusion of ZIKV RNA-reactive blood products but it is difficult to evaluate the effectiveness of this measure to prevent ZIKV-TT infection, which is a rare event.